[smartpuppiepets]

i like to stick to science diet or royal Canin and if they do not like to eat it as much i feed purina PROPLAN small breed formula, they love to eat that and i never had problems with it. I would think that a very high protein food is not good for yorkies, if you research more on the breed and how delicate their digestive system is anyways it could make my idea make more sense to you.
I used to feed Royal Canin only, but that food is a bit too rich and i find they do not eat enough, never had problems with it but my guys used to be lighter in weight, now they eat the proplan, you can touch the kibble and you will notice that has less fat in it, they like to eat it a little more and i found they keep a little bit more weight just because they eat some more of it, coat is great and shiny, more playful , the science diet is the food my vet recommends... and i tried but they absolutely do not eat it, they eventually eat some if they are starving , but just enough to get by.... I hope this can give you some insights and some light in your questions towards too rich of a food for a yorkie.
Good Luck with your baby, hope it gets better soon and this turns out to be nothing.